Merge pull request #17 from little-red-rover/16-refactor-as-c++

Refactor as c++

.clangd

@@ -1,4 +1,4 @@
 CompileFlags:
   CompilationDatabase: build/
-  Add: -Wno-unknown-warning-option
+  Add: [-Wno-unknown-warning-option, -xc++, -std=c++20]
   Remove: [-m*, -f*]

.devcontainer/devcontainer.json

@@ -11,13 +11,11 @@
             ]
         }
     },
-	"features": {	
-		"ghcr.io/duduribeiro/devcontainer-features/neovim:1": {
-            "version": "stable"
-        },
+    "features": {	
+		"ghcr.io/duduribeiro/devcontainer-features/neovim:1": {},
 		"ghcr.io/duduribeiro/devcontainer-features/tmux:1": {},
 		"ghcr.io/devcontainers/features/node:1": {},
-        "ghcr.io/devcontainers-contrib/features/ripgrep:1": {}
+        "ghcr.io/jungaretti/features/ripgrep:1": {}
 	},
 	"mounts": [
 		"source=${localEnv:HOME}/.config,target=/root/.config",	

CMakeLists.txt

@@ -2,6 +2,8 @@
 # CMakeLists in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.5)
 
+# set(IDF_TOOLCHAIN "clang")
+
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 
 project(lrr)

README.md

@@ -1,3 +1,80 @@
 # Little Red Rover Firmware
 
 Firmware for the ESP32-S3-MINI-1 built into the rover's body.
+
+This project uses the Espressif IoT Development Framework (espIDF) [read more](https://github.com/espressif/esp-idf).
+
+## Birds Eye View
+
+Little Red Rover's firmware is responsible for three tasks:
+1. Establishing Wi-Fi connectivity
+2. Reading information from sensors (LiDAR, IMU, wheel encoders)
+3. Writing commands to actuators (wheel motors)
+4. Relaying sensor data and recieving commands over a TCP connection
+
+Because all high level algorithms are run on the base station computer (see [lrr_ros](https://github.com/little-red-rover/lrr-ros)), the rover itself has very little control logic.
+Instead, it's optimized for network transmisison and reception.
+
+## API
+
+The rover hosts a TCP server listening on port 8001.
+When connected to the rover's hotspot, the ESP32-S3 has the IP address `192.168.4.1`, making the TCP server address `192.168.4.1:8001`.
+
+Send commands using the format defined in the protobuf schema [messages.proto](https://github.com/little-red-rover/lrr-firmware/blob/16-refactor-as-c%2B%2B/components/communication_stack/socket_manager/messages.proto).
+
+To recieve data, the client must first send a SubscribeRequest message with the relevant OutgoingMessageID.
+The rover will then begin sending data to that port.
+
+TODO: update link on C++ PR merge.
+
+## Composite Technologies
+
+### FreeRTOS
+
+The system is based on FreeRTOS, a realtime embedded operating system (RTOS).
+FreeRTOS provides scheduling and mutlithreading utilities that are crucial for running efficiently in an asynchronous networking environment.
+
+### NanoPB
+
+In order for data to be transmitted over the network, it needs to be serialized appropriately.
+This project uses [Google's ProtocolBuffers](https://protobuf.dev/).
+Specifically, the firmware uses an embedded focused implementation of ProtocolBuffers called [NanoPB](https://jpa.kapsi.fi/nanopb/).
+
+## Project Structure
+
+* `/main`
+  * `lrr_main.cc`: The firmware entry point. Initializes drivers.
+* `/components`
+  * `/communication_stack`
+      * `/wifi_manager`:
+         * Initializes wifi
+         * Handles provisioning (connecting to Wi-Fi using remotely provided credentials)
+         * Connects to Wi-Fi
+         * Sets up NAPT so that users can connect to the internet through the rover
+      * `/socket_manager`:
+          * Multithreaded TCP server implementation
+          * Manages multiple client connections, data subscriptions, and general network IO
+  * `/hardware_drivers`
+      * `/battery`:
+          * Measures battery using the ADC
+          * Telemeters battery level data
+      * `/drive_base`:
+          * Integrates encoder pulses using the ESP32-S3 pulse counter module (PCNT) 
+          * Drives PID control for the motors
+          * Accepts joint state commands as JointCmd messages (see protobuf message definition)
+          * Telemeters joint state information as JointState messages
+      * `/imu`:
+          * Reads data from the IMU over I2C
+          * Telemeters IMU data as IMU messages
+      * `/lidar`:
+          * Reads data from the LD20 LiDAR over UART
+          * Telemeters LiDAR data as LaserScan messages
+      * `/status_led`:
+          * Provides a function to set the status LEDs in response to system events
+
+## Development Environment
+
+The `/docker` and `/.devcontainer` folder provide a devcontainer environment for development.
+The docker container uses privilaged mode to flash the ESP32-S3 over USB. The privilaged flag is not supported on MacOS or Windows, so this may not work for you.
+
+Cross platform build instructions are a WIP.